LiDon Technologies proposes to develop an improved aerosol delivery system. The proposed system, Concentrated Aerosol Delivery and Quantization System, CADAQS, will fulfill the need to acutely deliver high particle number concentrations of aerosols to small animals (rats, young rabbits, and guinea pigs: wt < 1000 g), while enabling the regional quantization of their deposition in the lungs. The CADAQS consists of 3 subsystems. A) A two stage aerosol concentrator, TSAC, concentrates aerosols of 1-5 mu m AMMD from 10 to 100 times. B) A small Animal Aerosol Delivery System, SAADS. C) A Quantitative Aerosol Deposition System, QADS. In this Phase I project, we will focus on the construction and testing the two stage TSAC. Following the optimization of the parameters of the TSAC, the particle size (mass median aerodynamic diameter) and the concentration factors will be determined for both aqueous and solid aerosols using a Marble-Miller cascade impactor. The aqueous aerosols, generated from fluorescein solution, will be determined spectrophotometrically. The solid aerosols, generated from radiotagged iron oxide sol, will be determined by a V-nuclear technique. In Phase II, the TSAC system will be integrated with the SAADS and QADS. This CADAQS system will then be tested using rats. The TSAC, the SAADS, and the QADS are designed to be sold as stand-alone devices as well as components of CADAQS. Such a system is not available commercially. LiDon believes this system will greatly facilitate and enhance the processes of drug discovery, respiratory toxicology and pharmacology through the delivery of drugs to the respiratory tract for both local and systemic drug delivery. PROPOSED COMMERCIAL APPLICATIONS: This system is used to deliver concentrated aerosols to the respiratory tract of small animals while enabling the regional quantization of the deposited aerosol. This system can also act as a forerunner for the development of technologies for measuring cardiopulmonary function and aerosol deliveries to premature infants.